The return of rain to western New York heralds the start of late summer and once again its the season for occasional thunderstorms to come rumbling through.  Earlier this year, Consumer Investigation looked at how to protect your system from the damaging effects of lightning.  It generated a number of questions from readers who wanted to learn more about how their systems could be affected.

"My question is about my cable modem.  I have an upcoming vacation and plan to unplug my PC while I am gone.  Is it acceptable to unhook the cable connection from my PC for a period of time?  When they installed my cable modem they told me to leave the modem on at all times; is this correct?" -- Mary Beth P.

One of the nice features about a cable modem is that users are always connected to the Internet.  There is no delay in logging in or out - just plug things in, turn them on and your connection is ready and waiting for you all the time.  There is no reason to turn off or disconnect the modem when you are not using the connection which is probably what the Time Warner installer meant when he told you to leave the modem on.  It is perfectly safe to disconnect the modem during vacations as long as you are comfortable with reconnecting it when you return.  When you initially power on the modem, it will likely have to secure a new identification address (for technical folks, that's an IP address), but once that is done the connection should work as before.

If it doesn't re-establish a connection, you should call your ISP and report the problem.

As I reported this spring, a good Uninterruptible Power Supply (UPS) can provide your system with both backup power and surge protection from nearby lightning strikes.  John R. asks which UPS', if any, contain an isolation transformer.  Basically, these transformers isolate your system from the variability of the local power grid, ensuring that your PC receives only clean power free from "noise" and transients that can accompany the voltage over standard wiring.  This is useful for sensitive electronic equipment.  Most isolation transformers are found in commercial applications where power protection is absolutely vital.  Most quality UPS manufacturers do build in some power filtering and monitoring technology, but not to the level found in professional grade equipment.

Thankfully, most PC power supplies and components are designed to work under a range of less-than-perfect power conditions, and computer components will be obsolete long before they could be affected by normal voltage variability found on the local power grid.  The real danger to computer equipment comes from voltage spikes.  Thankfully, most storms here in western New York are not nearly as serious as the heart-stopping storms in the southeast, but all it takes is one nearby strike to do a great deal of damage.  In fact, some voltage spikes can occur because of a failure of equipment on a nearby pole even during perfect weather.

Marge Z. wrote asking how protected she is from lightning with her existing surge protector:

"I have a good surge protector plus I have one that was inserted into the wall for me by a friend who said I don't have to unplug my system during a lightning storm, but do you think it would be better to unplug it just to be safe?" she wrote.